The red cell distribution width (RDW) predicts mortality, including among cardiovascular, pulmonary, trauma, and other patients, and in the general population. RDW is the standard deviation (SD) of the red cell volume divided by the mean corpuscular volume (MCV). Because higher MCV also predicts mortality risk, it sonsidered that RDW-SD (the RDW numerator) predicts mortality more strongly than RDW.
A normal range for red cell distribution width is 12.2 to 16.1 percent in adult females and 11.8 to 14.5 percent in adult males. If you score outside this range, you could have a nutrient deficiency, infection, or other disorder. However, even at normal RDW levels, you may still have a medical condition.
What if red cell distribution width SD RDW-SD is high?
If your RDW is too high, it could be an indication of a nutrient deficiency, such as a deficiency of iron, folate, or vitamin B-12. These results could also indicate macrocytic anemia, when your body doesn't produce enough normal red blood cells, and the cells it does produce are larger than normal.
In general, red cell distribution width (RDW) has recently been associated with the risk of cardiovascular disease and all-cause mortality. The underlying mechanisms remain unresolved, but high levels of RDW may be caused by inflammation or poor nutritional status.